Vol 110 (2013)

Journal of the Entomological Society of British Columbia

A female Agapostemon (probably texanus) gathers nectar from a diffuse knapweed flowerhead. Halictine bees run that gamut from true eusociality to solitary nesters and are as such an excellent system for studying the evolution of hymenopteran social behaviour. Agapostemon species can be communal nesters, but A. texanus as a species seems to be pretty steadfastly solitary in its habits. Like other ground nesting bees, it has an annual life cycle where overwintering females emerge in the warm part of the spring, build vertical burrows in soil and provision individual eggs with a pollen ball to support larval development all the way through to pupation. Males become abundant in late summer and fall and mated females will overwinter in diapause to start the cycle over the following year. Unlike the bee, which is native, diffuse knapweed is an invasive pest in western rangelands.

Photograph details:

Photograph by Robert Lalonde (UBC Okanagan). Made with a Canon EOS digital rebel T2i equipped with a Canon 100mm f2.8 macro lens in natural light; ISO 800; f8 at 1/250 sec; on 8 July 2013 at 1557h on the UBC Okanagan campus in Kelowna, British Columbia.